Coal burner



Feb. 18, 1936. A. ADRIANOFF 2,031,199

COAL BURNER Filed Feb. 26, 1935 A'exondre. A fj IN-VE NT E,

6mm 23 BM v.

Patented Feb; 18, 1936 UNITED STATES PATENT OFFICE Application February26, 1935. Serial No. 8.294 In Belgium August 17, 1934 Claims.

My present invention relates to improvements in coal burners used,namely, for the combustion of very small size coals.

It more particularly concerns burners in which 5 the fuel falls, from ahopper, on an inclined surface and which comprises a device for theinsuffiation of air into the fuel.

v In the burners of this type, the walls of the combustion chamber aregenerally surrounded 1 by. a water chamber which serves to cool themdown and to recover the heat arising from the combustion of the 'coal.The heating of the cooling water is however much more intense in theclose vicinity of places where the combustion proceeds and namely inplaces where curvatures resulting in narrow passages occur in the wallsof the combustion chamber to form the slide surfaces, the blow-ports,etc. The water circulation does not operate therefore so freely at theseplaces, which may cause an excessive rise in temperature of the water.

On the other hand, in existing burners, the insufflation of air into thefuel is generally soon hindered by the formation of clinkers.

The present invention has for its object to avoid these drawbacks and toprovide a burner particularly simple in construction, enabling, namely,to avoid a retardation of the combustion when clinkers are formed.

With this object in view, my invention essentially consists in thespecial arrangements and combinations of parts hereinafter fullydescribed and pointed out in the appended claims.

The annexed drawing shows by way of example a form of embodiment of acoal burner constructed according to the invention.

Figure 1 is a vertical cross section through a plane perpendicular tothe axis of the coal burner.

Figure 2 is a vertical cross section through a plane according to theaxis of the coal burner.

In these figures, I designates the combustion chamber which ispreferably formed by a cylindrical wall 2, surrounded by a water jacket3, comprised between the wall 2 and an outside wall 4.

According to the invention, the wall 2 forms on a portion of its length,an inclined ledge 5 laterally disposed and leading by'a tongue-shapedcurve 6 to a surface I which through the curve 8 joins again the innercylindrical wall 2, thus providing, on the one hand, a water chamberbetween the surface I and the inclined ledge 5, and on the other a freespace between the surface I and the bottom of the cylindrical wall 2.

Above the inclined ledge 5 is an opening 9 laterally disposed andconnected to a hopper adapted to receive the coal, whilst under thesurface I is a nozzle In for the injection of air under pressure. 5

The coal, which falls through the opening 9, forms inside the combustionchamber l a heap with a main slope ll whilst, from the end of the tongue6 is formed another slope i2 in the free space I3 in whichair underpressure is blown. 0

The combustion chamber i is closed in front by a door ll, fixed on aring l5 connected to the cylinder 2, and is at the back in communicationwith the inside of a hearth or of a central heating boiler, forinstance, through a conduit or duct. 15 i6 formed by a ring H which isconnected to the cylinder 2.

The rings l5 and II are hollow and form annular ducts l8 and i8 whichare connected to the air blowing device and through which passes air 20which can enter into the combustion chamber I, through openings 20 and2! provided above the front slope 22 and the back slope 23 of the heapof coal, which latter falls in through the opening 9.

The coal burner thus constructed operates as follows:

The fuel falls by gravity through the opening 9, partly. fills thecombustion chamber I forming therein a heap with a top slope II, a front30 slope 22 and a back slope 23. The fuel lies on the bottom of the wall2 and forms further in the free space I3 a supplementary slope [12 whichcloses this space i3. In the latter the nozzle It for the insufllationof air opens. It follows that 35 the air thus blown in completely fillsthe space 53 and is introduced into the fuel through the slope i2.

In fact the air under pressure will tend to follow preferably the lineof least resistance which 40 runs along the bottom wall of the cylinder2.

It follows that the clinkers which form at the lower end of the inclinedledge 5 do not constitute a bar to the passing of the air. On thecontrary, clinkers formed at the lower end of the 45 inclined ledge 5facilitate to some extent the passing of the air through the mass offuel, by the progressive diminution of the thickness of the heap.

On the other hand, the end of the nozzle is not 50' in contact, as isthe case in most existing burners, with the ignited mass of fuel, andthe bottom edge of the inclined ledge 5 is outside the zone ofcombustion having the highest temperatures, since the combustion of thecoal takes place 55 mainly along the slope l2 and along the lowerportion of the wall of the cylinder 2. Moreover, the bottom part of theinclined ledge 5 is well cooled down by the water which circulateseasily in the chamber formed by this incline and the surface I.

It should be noted that when the coal is ignited, it is possible toobtain a slow combustion by interrupting the mechanical airinsufllation, without fear of complete extinction, as the slowcombustion can take place with an ordinary draft; the heated aircontained in the rings l5 and I1 enables to relight the distillationgases when the air insuiiiation device is again brought into action.

What I claim is:

1. In a coal burner in combination with a combustion chamber providedwith a water Jacket, an inclined ledge laterally disposed in the saidchamber and leading by a tongue-shaped curve to a surface which throughanother curve joins again the inner wall of the combustion chamber,whereby a water chamber is obtained between the said surface and thesaid inclined ledge and a free space is formed under the saidsurfacebetween the latter and the bottom of the said wall, a slope of coalbeing formed in the said free space, and means whereby air is blown intothe said free space above the said slope of coal.

2. In a coal burner in combination with a combustion chamber providedwith a water jacket, an inclined ledge laterally disposed in the saidchamber and leading by a tongue-shaped curve to a surface which throughanother curve joins again the inner wall of the combustion 1 chamber,whereby a water chamber is obtained between the said surface and thesaid inclined ledge, the distance between the said surface and thebottom of the combustion chamber being such that a slope of coal isformed in the said space, and means whereby air is blown into the saidspace.

3. In a coal burner in combination with a combustion chamber providedwith a water Jacket, an inclined ledge laterally disposed in the saidchamber and leading by a tongue-shaped curve to a surface which throughanother curve joins again the inner wall of the combustionchambenwhereby a water chamber is obtained between the said surface andthe said inclined ledge, the distance between the said surface and thebottom of the combustion chamber being such that a slope of coal isformed into the said space, and means whereby air is blown into the saidspace, an opening for the introduction of the coal being arrangedlaterally in the said combustion chamber in such a manner that an upperslope, a front slope and a back slope are formed.

4. In a coal burner in combination with a combustion chamber providedwith a water jacket, an inclined ledge laterally disposed in the saidchamber and leading by a tongue-shaped curve to a surface which throughanother curve Joins again the inner wall of the combustion chamber,whereby a water chamber is obtained between the said surface and thesaid inclined ledge, the distance between the said surface and thebottom of the combustion chamber being such that a slope of coal isformed into the said space, and means whereby air is blown into the saidspace, an opening for the introduction of the coal being arrangedlaterally in the said combustion chamber in such a manner that an upperslope, a front slope and-a back slope are formed, and means wherebysecondary air is adapted to be introduced above the front and backslopes in the combustion chamber.

5. In a coal burner in combination with a combustion chamber providedwith a water jacket, an inclined ledge laterally disposed in the saidchamber and leading by a tongue-shaped curve to a surface which throughanother curve Joins again the inner wall of the combustion chamber,whereby a water chamber is obtained between the said surface and thesaid inclined ledge forming together a tongue and a free space under thesaid surface of the tongue between the latter and the bottom of the saidwall, whereby a slope of coal is formed in the said free space, andmeans whereby air is blown into the said free space and is projectedunder the face of the tongue and is then dispersed before passingthrough the heap of coal.

ALEXANDRE ADRIANOFF.

